Multiple Experts vs. Multiple Methods: Combining Correlation Assessments

Robert L. Winkler () and Robert T. Clemen ()
Additional contact information
Robert L. Winkler: Fuqua School of Business, Duke University, Durham, North Carolina 27708-0120
Robert T. Clemen: Fuqua School of Business, Duke University, Durham, North Carolina 27708-0120

Decision Analysis, 2004, vol. 1, issue 3, 167-176

Abstract: Averaging forecasts from several experts has been shown to lead to improved forecasting accuracy and reduced risk of bad forecasts. Similarly, it is accepted knowledge in decision analysis that an expert can benefit from using more than one assessment method to look at a situation from different viewpoints. In this paper, we investigate gains in accuracy in assessing correlations by averaging different assessments from a single expert and/or from multiple experts. Adding experts and adding methods can both improve accuracy, with diminishing returns to extra experts or methods. The gains are generally much greater from adding experts than from adding methods, and restricting the set of experts to those who do particularly well individually leads to the greatest improvements in the averaged assessments. The variability of assessment accuracy decreases considerably as the number of experts or methods increases, implying a large risk reduction. We discuss conditions under which the general pattern of results obtained here might be expected to be similar or different in other situations with multiple experts and/or multiple methods.

Keywords: combining forecasts; correlation assessment; assessment methods; expert judgment (search for similar items in EconPapers)
Date: 2004
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (27)

Downloads: (external link)
http://dx.doi.org/10.1287/deca.1030.0008 (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:inm:ordeca:v:1:y:2004:i:3:p:167-176

Access Statistics for this article

More articles in Decision Analysis from INFORMS Contact information at EDIRC.
Bibliographic data for series maintained by Chris Asher ().